Chronic renal denervation prevents glomerular hyperfiltration in diabetic rats

Area of Science:

• Nephrology
• Diabetology
• Physiology

Background:

• Glomerular filtration rate (GFR) increases with amino acid infusion, but this is reduced by chronic renal denervation in rats.
• Early diabetes mellitus is characterized by glomerular hyperfiltration, a phenomenon whose underlying mechanisms require further investigation.

Purpose of the Study:

• To determine if renal denervation can prevent the glomerular hyperfiltration observed in the early stages of diabetes mellitus.
• To investigate the role of renal nerves in mediating structural changes in the kidney during early diabetic nephropathy.

Main Methods:

• Sprague-Dawley rats underwent bilateral renal denervation prior to streptozotocin-induced diabetes mellitus.
• Glomerular filtration rate was assessed using clearance experiments two weeks post-diabetes induction.
• Glomerular volume was estimated by measuring the cross-sectional area of Bowman's capsule in fixed kidney slices.

Main Results:

• Diabetic rats with intact renal nerves exhibited significant glomerular hyperfiltration compared to non-diabetic controls.
• Renal denervation in diabetic rats normalized GFR to levels observed in non-diabetic controls.
• Diabetic nephropathy-induced glomerular enlargement was prevented by renal denervation.

Conclusions:

• Renal nerves are critically involved in mediating glomerular hyperfiltration in experimental diabetes mellitus.
• Preventing sympathetic nerve stimulation to the kidney abolishes structural changes like glomerular enlargement in early diabetic nephropathy.